so let us melt, and make no noise
by LittleLostStar
Summary: When a mission to the South Pole goes awry, Prince Zuko awakens in the hut of a healer named Katara with a damaged heart and his bending ripped away. Finding the last waterbender is Zuko's only chance to regain his honour and return home; but Katara is protecting an ancient secret of her own, and it will upend everything Zuko thought he knew about destiny, love, and bending itself.
1. Prelude

Hello, pals! I've never written Zutara before, and I'm really excited to start. I hope you all enjoy, and if you do, please let me know! :-D

 **Please note that the rating is subject to change.**

* * *

The wind seemed to come from every direction, battering the inn with relentless fury, its ghostly howl penetrating through the thick blocks of ice and wooly hides hung on the wall. It was warm inside, at least, filled with carefully kindled firelight and the heat of bodies covered in thick coats, their features barely visible through the layers of fabric covering every possible inch of exposed skin.

The Tiger Seal was the very last outpost of the South Pole, and as such it collected all manner of oddballs and outcasts. Some stopped there to refuel and rest before they took off into the great unknown; others lived there permanently, having sought a home away from home and finding one at the very end of the whole world. The inn was still run by the same Water Tribe families who had first founded it over a hundred years before; even as the Fire Nation had raided village after village, the Tiger Seal had remained, steadfast and sturdy, offering a bed and a meal to anyone who came through its doors. The staff took pride in their heritage, uniquely able to flaunt their traditions without fear of repercussion, and were more than eager to tell old Water Tribe stories to anyone with ears, no matter how disinterested they might be. The inn buzzed and hummed with conversation, a hive of human activity bracing against the unrelenting cold.

The traveler was perched at the bar, gloved hand wrapped around a glass of something warm and alcoholic, when he heard the bartender say three words that made him go cold all over again.

"So then she ran, y'see? The last waterbender. And no one's seen her since."

 _The last waterbender._

The traveler knew better than to react; he'd been trained to remain stoic even in the most horrifying of circumstances, and a few gossipy nobodies at a remote pub wouldn't faze him. That said, his father used to say that more information was always better before a battle, so he perked up an ear and tried to eavesdrop around the fur trim of his hood.

"That's incredible," the tourist said. "Where did she go?" The excitement and curiosity in her voice was thick like treacle, and the traveler rolled his eyes and took another sip of his drink.

"Down to the pole proper, where no one can survive," the bartender replied. "She's got a whole fortress she made there. No one can find it, and no one who enters it lives to tell the tale."

"That's nonsense," another patron slurred, far too loudly. "If no one's lived, how'n—how d'you know where she is?"

The bartender shrugged. "That's just what my ma told me," he said. "She used to say that the waterbender was the heart of the whole Water Tribe, and she was tasked with keeping all our old treasures safe until the war was over."

"No," the drunk patron cut in again, "it's that her heart is made of gold. Anyone who can take it from her will be rewarded beyond their wildest dreams."

 _I bet that's a lie,_ the traveler thought to himself, and couldn't help but smirk. _I'll bet her heart is just as much flesh and blood as mine. But no matter how many worthless trinkets she hoards, these idiots are right about one thing: her heart is priceless, and when I take it from her I will be rewarded indeed._

"That's ridiculous," someone else shot back. "How could a woman's heart be made out of gold?"

"I don't know!" the drunkard replied. "She's a witch, ain't she? It could happen."

"Waterbending isn't witchcraft," the bartender said, refilling the traveler's cup as he passed by. "She's a human, just the same as you or me. Probably over a hundred years old by now."

This was all getting just a bit too chummy for the traveler, and he downed his drink in one go and tossed a few silver pieces onto the bar, thinking already of his bed upstairs—the last chance for any real comfort for a very long while. But as he went to slide off his stool, a new voice cut through the din of the room, and this one made him stop in his tracks.

"You're all fools," it said, and the traveler turned to see an old crone of a woman standing there, her eyes quick and sharp. "The waterbender isn't some children's adventure story. She possesses all of the knowledge and power of our once-great tribe; she's the strongest bender that's ever been born. Do you know how many of you I've seen pass through this inn? Heads full of empty dreams of fame and glory, so distracted by the promise of riches that you don't even realize you're walking into a trap until it's too late. The waterbender has powers the likes of which haven't been seen in decades; those who knew exactly what she was capable of have all died off by now. You look around and see our traditions and ways, and you think we're some kind of primitive culture that hasn't known glory. But waterbending isn't fancy tricks; it's more dangerous and incredible than you could ever imagine."

The drunkard laughed, a short burst of denial, but the old woman paid him no mind; her gaze was squarely on the traveler, and he stared at the floor to avoid meeting her eyes.

"If I were smart," she said, "I would abandon any notions of trying to find the waterbender, no matter your reasons. Because you won't find her; you'll die in the snow first, and no one will know to mourn you. But even if you do? The waterbender will see right through you. She'll know every transgression, every sin, every scar. And her judgement will be swift and merciless."

The traveler kept still, even as his heart pounded against his chest, and the woman's words sank in.

 _Her judgement will be swift and merciless._

He shook his head of the thought. That wasn't enough to stop him; he would simply need to be more swift, more merciless. He had plenty of experience with that.

With his bill paid, the traveler climbed up to his room, shut the door, and finally pulled off his hood. A polished piece of glass was hung over the washbasin, and he caught a glimpse of his reflection and stopped.

The months of travel were beginning to wear on him already; he had lost weight, and the angles of his face seemed particularly harsh in the cool light of the moon outside. He glowered almost by force of habit, but his heart wasn't in it; as his expression fell, he swore he could see a flicker of the young boy he once was—handsome and full of promise, too emotional for his own good and too soft to survive.

That was why he was here, at the very end of the world, in the coldest place imaginable, and about to be a whole lot colder. That was why he had traveled for so long, from ship to ship and port to port, first with an entourage and then with just a small staff and then eventually alone. Everyone around him always seemed happy to leave, and he really couldn't blame them; there was no honour in serving a monster, no glory to be found in following the orders of an embarrassment like him. It was just as well, then; the South Pole was a lonely place, and his quest fell on him and him alone. It seemed only right that the last part of his journey would be the hardest, but he was so close. Just a few more miles, just a few more nights, just a single horrifying task to accomplish, and then he could finally go home again.

 _Bring me the heart of the last waterbender_. The tallest order imaginable, and yet he would do it. He would do anything, if it meant restoring his honour and setting things back to the way they used to be.

The old woman's warning echoed back to him: _The waterbender will see right through you. Her judgement will be swift and merciless._

Without thinking, the traveler reached his bare hand up to the left side of his face, trembling fingertips tracing the sickeningly familiar ridges of the burn that flamed across his eye and down his cheek.

 _Every transgression. Every sin. Every scar._


	2. One: the loneliest landscape you knew

The very bottom of the world was a place that defied expectation and explanation. At least that's how it seemed to Prince Zuko, as he exhaled a puff of heated air that quickly dissipated into the whirling snow around him.

He had been traveling for a week, though he was starting to doubt his own ability to tell time. Leaving the Tiger Seal had seemed so easy; no one had tried to stop him, even as he began walking directly due south. In those first moments of marching, his pack strapped to his back, Zuko thought that maybe this wouldn't be too difficult after all; now, as the snow hit his exposed skin like tiny pinpricks, he found himself reconsidering just how dangerous the weather was, and contemplating with dread how much worse it might become. He was no fool; he knew the South Pole would be cold. He had traveled all over the world, in the first years of his banishment, and had experienced the biting pain of a blizzard before. But he didn't ever imagine it would be like this.

Perhaps the staff of the Tiger Seal had become used to the determination of such travelers, whose ambitions outstripped their sense of self-preservation; if they'd made it all the way to the inn, then they weren't going to turn back because of a few severe weather warnings from the locals. Perhaps they _did_ warn most people—people who could smile, whose faces weren't difficult to look at, whose failure didn't cling to them like a stench that could never be washed off. Perhaps they knew exactly who Zuko was, and thought it was better that he die down here, alone in the snow—one less Fire Nation monster to hunt them and theirs. Zuko wouldn't be surprised.

The snow around him was blinding, the horizon line all but obliterated. Nothing but blank whiteness for as far as the eye could see, and nothing to keep Zuko distracted and prevent his mind from wandering. The cold had numbed his body, dulling the pain in his shins that came from traipsing through the snow banks, but the agony of the mind remained sharp and cruel, no matter where he was.

 _Bring me the heart of the last waterbender._ His father's order echoed in his head, whispering over the howl of the wind. At the time, those eight words had seemed like a benediction, a peace offering, a final trail on the map that could guide Zuko back home. He had wandered the earth for six years after his banishment; he was the Exiled Prince, unwelcome wherever he went. He had held out as long as he could, determined to keep his head high and his pride intact—what was left of it, anyway—before he had come crawling back to Caldera, head bowed low, begging for some way he could be redeemed.

It wasn't the jeers of the peasants that did him in, in the end. It wasn't the news that his uncle Iroh, perhaps the last man who had shown Zuko kindness, had taken ill. It wasn't even the rumours that his sister Azula was being groomed for succession. Zuko had just become too homesick to be afraid anymore.

It was humiliating. Every moment of his return had been torture; sneaking through the city like a common thief, the silence in the palace hallways, his sister's high-pitched giggle heard behind a door as he passed. Zuko had half-expected his father to just kill him on sight; that was the standard punishment for those who broke their exile and returned to the Fire Nation. But Ozai had spared his son the flames this time; as Zuko prostrated himself, his forehead hovering less than an inch from the smooth marble floor of the throne room, the Fire Lord had instead simply waited. Seconds had crawled by in agonizing slow motion, and Zuko never moved a muscle, even as he braced himself to hear the _whoosh_ of fire and feel the heat bearing down on him, searing his flesh, making countless nightmares a reality.

Ozai had made him wait for over fifteen minutes before he finally said those eight words: _bring me the heart of the last waterbender._

By the time Zuko raised his eyes to the throne, his father was already gone. He had slipped away from the palace just as quietly as he'd entered, his hooded robes pulled up over his face, had told no one of his new quest. He had boarded a ship bound for the southern tip of the Earth Kingdom, and from there had hopped from vessel to vessel until he'd made his way to the pole, utterly alone. Being exiled was bad enough; to have come back, begging for mercy? That was a whole new level of dishonour, a whole new dark void of self-loathing that could rot and fester in his mind with each passing day.

He stopped his trek for a moment, his upper lip curling reflexively as a wave of shame washed over him. _The waterbender will see right through you,_ the old woman had said. There would be more than plenty for her to see in Zuko; it wasn't a question of whether or not she would find him unworthy, but rather just how many of his transgressions she would drag up as proof before—

He closed his eyes. _I won't let her get that close._

There were no other options. There would be no substitute. He would accept nothing less. Crown Prince Zuko of the Fire Nation would return triumphant and take his rightful place by his father's side, and this whole horrible ordeal could just be forgotten.

But _Agni_ , it was cold. Zuko clenched his jaw, trying to keep his teeth from chattering.

The snow came up to his mid-thigh by now, turning each step into an ordeal of quick capture and agonizingly slow release, over and over again. He had packed light, but not light enough; he'd already discarded several less-than-crucial items and was starting to wonder which of the crucial ones he could do without. He had placed them down on the trail, in a vain attempt to mark himself a path home, but when Zuko looked back, all he could see was a blanket of pure white snow, his footsteps disappearing before his very eyes.

He'd stopped to make camp only three times, when the exhaustion had become profound enough that he couldn't drag himself even one step further. Zuko wasn't entirely naive; he had consulted experts, learned how to survive in the winter like this. How to dig himself a burrow in the snow, how to insulate himself as much as possible, how to keep his compass in hand at all times lest he lose his way and go in endless circles.

In theory, that was all well and good. In practice, Zuko had to admit that things were not going quite as smoothly as planned. As he got further to the bottom of the world, the compass seemed to go haywire more and more. He knew that the sun in the South Pole was going to be weaker than he was used to, but as Zuko trekked south, the light dimmed, until one day it disappeared completely. It hadn't risen in days, or at least that's what it felt like. The winds got worse with every passing hour, faster and colder than he thought imaginable. Zuko, who had trouble seeing out of his left eye at the best of times, had completely surrendered all hope of actually being able to watch where he was going, and he grumbled muttered curses into the scarf that covered his mouth and nose from the cold.

"Cold" was an understatement. Cold was a four-letter word. Cold was meaningless, undefined, beyond and without limits. Zuko was the Crown Prince of the Fire Nation, born in the capital city of Caldera, damn it; he had been raised in the sun, as was his birthright. He was a firebender; he drew power and energy from the sun, and the South Pole was one of the darkest places Zuko had ever seen. His Phoenix tail did nothing to shield the wind from his ears, and tiny pinpricks of snow seemed to hit his bare scalp no matter how tightly he retreated into the hood of his coat.

A lesser man might stop, make camp again, try to wait out the storm and resume his journey once visibility was better. But Zuko was better than that; he _had_ to be better than that. He knew that it was no accident that the last stretch of his journey was taking place in such a world of darkness; that was how destiny worked. This was his final test, his chance to prove once and for all that he deserved his title, his family, his place in the sun.

All Zuko had to do was kill an innocent old woman and cut out her heart.

The winds suddenly whipped up around him, almost pulling his coat clean off his body. Zuko gasped as a chill shot straight through him, reverberating in his chest and making his arms tremble so badly that he lost his grip on the compass, which dropped silently into the snow and promptly disappeared.

"No!" Zuko yelled, falling to his knees, digging through the snow to no avail. Visibility had dropped even further; he couldn't see much farther than his own hand directly in front of his face. The cold seemed to be seeping through his thick coat, crawling up and into his skin, settling into his core. He sat back on his knees and closed his eyes, trying to find his root, his uncle's voice rising to the forefront of his mind: _fire comes from the breath._

Inhale. Exhale. Zuko could feel his inner fire, burning brightly even as the storm tossed him around. He drew from it and exhaled a long breath of hot steam, hoping to warm the scarf on his face, but the air seemed to go right through the fabric and out into the night.

 _Fuck._ He pulled off one glove and snapped his fingers, pulling a flame out of thin air to sit in his palm, but as Zuko brought his hand near to his face, the fire whipped and flickered and suddenly went out. His second attempt gave the same result, as did his third, before Zuko felt his fingertips go numb and hastily pulled his glove back on to avoid frostbite.

The blizzard wasn't stopping; in fact, it seemed to get faster, the wind coming closer and closer as it circled around him. Zuko staggered back to his feet, only for a huge gust to come up behind him, catching the wide span of his pack and knocking him head over heels, tumbling through the snow. As Zuko rolled, he struggled to disentangle himself before the straps pulled both his arms off; when he was finally able to sit up again, the pack was nowhere to be seen, just another snow-covered lump in a world of nothing but snow-covered lumps.

A surge of rage and frustration blazed through him and he pulled his hands into tight fists, fireballs erupting from each one, burning his gloves away. "You think that will stop me?" Zuko yelled to the sky, his voice disappearing into the howl of the wind, but the fireballs barely lasted three breaths before they were snuffed out.

This had never happened before. Zuko was no prodigy, not like his sister (he knew that all too well), but he had spent his time in exile training harder than he had ever trained before, and his firebending was incredibly powerful by this point. Despite what everyone said in jeering whispers, he was still Ozai's son; there was a flame that ran through his family, and he had it, even if he had struggled to find it initially. That fire didn't just... _flicker_ out with a strong gust of wind; even the most powerful blast from an airbending master wasn't enough to extinguish his power. And yet the blizzard took Zuko's fire easily, snuffing it away as if it had never been. He tried again and again, and each time his flames seemed weaker and weaker. But he had to keep going; his hands would freeze if he didn't.

Something brushed against Zuko's right hip: a tube in his belt with a message scroll, enchanted by the fire sages so that all he had to do was burn his message into the parchment and let the ashes go with the wind. They would travel to their destination and reassemble themselves when they arrived; no hawks required. Zuko could feel the flame of his inner fire blowing and flickering, as if the wind was inside him somehow.

 _You won't find her; you'll die in the snow first, and no one will know to mourn you._ Zuko had felt the woman's gaze on him, back at the Tiger Seal, and he'd looked away like a coward. Now her warnings were coming back to bite him.

With his hands shaking, he pulled the scroll out and managed to conjure up a weak flame. He inscribed his message— _I am Prince Zuko. I'm trapped in a storm, a week's walk south from the Tiger Seal inn. Send all available ships_ —and let the flame catch the paper, huddling over it so it wouldn't die out. The ashes rose into the air, the flecks of grey swirling around him like a tornado, caught by the winds and unable to break free. _Please,_ he begged silently. _Please find someone. Anyone. I can't stop here, not when I'm so close._

Nothing changed; the blizzard continued its relentless onslaught, creeping ever closer, trapping him in. _I have to get to shelter,_ Zuko realized. _I have to wait out this storm._

There was part of him, the cowardly and soft part of him, which knew that the storm could probably outlast him, instead of the other way around. Nonetheless, Zuko fell back to his knees and began trying to dig a cave in the snowbank, hissing in pain as his fire failed to protect his hands and his fingers began to freeze. The wind surged up again, blowing his hood off and wrapping his hair around his throat. He gasped, clawing at his neck, but he was trapped and blind and _definitely not starting to panic—_

He couldn't breathe. It was impossible to be calm if you couldn't breathe. Zuko pulled his knife from his belt, but his hands were trembling too much to risk bringing the blade anywhere near his throat, so he reluctantly reached up and began to slice off his Phoenix tail at the root, wincing as the knife jittered against his bare scalp. After a few tense moments of cutting, his hair fell away and Zuko gulped at the icy air, shivering as it entered his lungs.

 _Agni, I swear I'll never fight with Azula again if you let me live through this,_ he thought despite himself. _I'll light an offering at Grandfather's tomb every day for the rest of my life. I'll obey Father's every command. I'll stop searching for Mother. I'll—_

Zuko's eyes widened as the uniform white of the snow was broken by a dark silhouette that seemed to glow light blue around the edges. He opened his mouth to yell for help, but he couldn't make a sound; the cold seemed to be inside him now, crawling and spreading, freezing him from the inside out. The shape came closer, resolving into the unmistakable outline of a human being.

 _It's her,_ Zuko realized. _It has to be her. She's right there; she's come to me. I could end this right now. If I can just—_

A final wave of cold air slammed into him, and Zuko only had the briefest vision of a flame snuffing out before his head hit something hard and the darkness swallowed him.

.

 _In his nightmares, Zuko saw an outline of a woman in the snow, and he reached for her with a weak and trembling hand. She knelt down, murmuring something he couldn't quite make out, but her presence was soothing and kind and achingly familiar_ —Mother.

" _There you are," she said, in a voice not quite her own. "I was worried about you."_

Where are you? _he tried to ask._ Where did you go? Why did you leave?

 _His mother shook her head, as if she didn't even hear him, and reached out to the place just under Zuko's left eye—_

No, _he pleaded, reaching out and catching her wrist before she could touch the scar._ Not like this. The only good thing that came from you leaving is that you never saw me like this.

 _His mother smiled sadly and began to fade from view. Normally when he had this dream, Zuko would chase and chase without ever catching up to her; this time, he realized, he couldn't move his legs at all._

Please, _he thought, his voice cracking with tears even inside his head._ Please don't let me—

.

—he bolted upright, gasping for breath, crashing back into the waking world just as suddenly as he'd left it. His heart raced as his eyes slowly refocused and the blurry shapes all around him began to sharpen and resolve. Zuko was no longer stranded in the storm; he was in a room with clean white walls that seemed to smoke very gently, giving off odorless vapour that coated the floor like a thin mist. Instead of the snowbank, he was lying in a bed, covered in furs and blankets, his chest bare.

 _What the—_

"There you are," someone said—the same voice from his dream. Zuko blinked as the door in front of him opened and a young woman slipped inside. She couldn't be much older than he was, probably only nineteen or so; her skin was smooth and brown, eyes clear blue like gems, and she wore the unmistakable blue robes of a member of the Water Tribe.

"Where am I?" Zuko asked, wincing his demand coming out as an embarrassing croak. "Who are you?"

"Relax," the woman said, her voice soft and unhurried as she approached the bed. "You're safe. My name is Katara. I found you lost in the storm; you stumbled into quite the blizzard out there."

"You're telling me," he scowled. "How long have I been here?"

Katara shrugged. "Two weeks, give or take."

Zuko cradled his aching head in one hand, barely suppressing a groan. He'd been waylaid by half a month because of that Agni-cursed storm; he had no idea where he was, never mind any of his gear, so that was all going to be a pain to sort out before he could get back on track. With a huffed sigh, he threw the blankets off and swung his legs over the side of the bed.

"Oh, no, I wouldn't—" Katara began, but she was cut off as Zuko tried to stand and promptly collapsed into a heap on the floor. He groaned as she knelt beside him and helped him back up.

"Yeah, that's not going to happen for a little while, I'm afraid," she said once they settled back onto the bed. Zuko let out a shaky breath, watching his legs tremble from the exertion.

"What—"

"—You were out in the storm for...well, I don't know exactly how long, but you were dying. I brought you back here, and I've been healing you ever since, but it's going to take some time."

Zuko exhaled tensely, through pursed lips. "Great," he sighed.

"Can you tell me your name?"

Remarkable. It had been so long since no one had recognized him, and it made Zuko feel strangely calm. He exhaled again, smoother this time. "Zuko. My name is Zuko."

Katara held out a hand, which he shook reluctantly. "It's nice to meet you, Zuko," she said. "Would you like something to eat?"

At the mention of food, Zuko's stomach growled loudly, and she smirked.

"I'll take that as a yes, then."

As Katara rose to leave, Zuko finally looked down at his chest, where an ugly red scab now sat directly over his heart. He winced, shivering as he recalled how the cold had seemed to crawl into his body and consume him from the inside out. _Hypothermia is a hell of a thing,_ he mused to himself. _I can't believe I thought that my firebending was—_

He stopped.

The room was warm, but Zuko still felt cold, and something was _off_ ; something was wrong in his chest. He reached for his inner fire and came up with nothing. It had never been this weak before. It had never been this quiet, this tiny, this _dim_.

Zuko looked up, eyes wide, and saw Katara standing at the door again, now holding a tray of food. He looked back down at his hands and snapped his fingers, but nothing happened. He reached again for his inner fire, more desperately this time, but all he felt was a bitter spike of cold.

 _Where is it? What's wrong with me?!_ Zuko felt panic start to consume him as he desperately searched inside his mind, trying and failing to grasp any semblance of the heat he'd felt his whole life, and flinched away violently as Katara set the tray down on the mattress beside him.

"Zuko, listen—"

"What have you done to me?" he gasped, too shocked to try and cover the fear in his voice. "Why can't I bend?"

Katara raised both hands. "Please try to be calm," she said, which only made the creeping panic worse.

It was all wrong, profoundly wrong, _badly_ wrong. He felt empty, hollow, dark. Zuko swallowed around a huge lump in his throat, his heart pounding as he grasped the truth:

His inner fire wasn't just weak; it was _dead._

Katara's features began to swim as tears filled his eyes. She went to place her hand on top of his, but he yanked it away, and she sighed.

"The storms up here are full of magic," she murmured. "From the moon, and from the South Pole itself. The wind and the cold caused damage to your heart, and—and your chi is blocked."

He sat back, hitting the headboard with a thud, shaking his head in tiny motions back and forth, dreading the words he knew he was about to hear:

"I'm so sorry, Zuko. Your bending is gone."


	3. Two: the wishes i've made

"Gone?!"

Katara nodded. "Yes."

Zuko felt ill. "What do you mean, gone?"

"I mean that you can't bend; your spiritual connection to your ability has been severed."

Zuko ran his hand across the back of his head, swallowing a wave of revulsion and regret as his fingers grazed the spot where his Phoenix tail once was. "This can't be happening," he moaned.

Katara's mouth was set in a thin line. "I'd been told it was possible, but I didn't think I'd ever see it with my own two eyes, let alone have a chance to heal it—"

Zuko felt his anger building. "Well I'm _delighted_ to be your first test subject," he yelled, but the tone felt off, the words awkward as they left his lips. _Why don't I feel right?_

She sat back, appalled. "You're not my test subject!" she exclaimed. "I was trying to help you!"

Zuko lashed out his arm, sending the tray clattering to the floor. "Well you've clearly done a great job so far," he snarled. Katara stood up, arms crossed over her chest.

"If you don't want to be healed, just say so," she snapped back. "I want to help restore your bending, but if you'd rather be alone, then have it your way." And with that, she turned on her heel and walked out, slamming the door behind her.

The sound was the spark that ignited Zuko's anger in full, and he gave in to it as he always did; he threw his blankets off the bed, upended the side table with a shove, and whipped his pillow at the wall, where it caused ripples in the smoke. He pushed himself off the bed, weak limbs be damned, and sat with his back against the frame, a snarl on his lips, chest heaving as the fury coursed through him. But then he paused, face falling.

 _It's not right._

Zuko was more than acquainted with anger. Anger was part of what drove firebending; it was all about channeling the emotion into power, and maintaining a strict discipline over it. Anger was a powerful weapon, blazing and roaring and consuming everything in sight. Anger sat in his mind all the time, coiled like a spring, waiting to be unleashed. And while control was crucial, there was always the temptation to let go, to unleash the force in full, to let the inferno rise. The aftermath of an outburst was like a forest after a fire: quiet, eerie, and dormant, infused with a cathartic echo that soothed the reality of the damage done.

But Zuko didn't feel any of that.

Instead, the anger pulsing through him felt flattened, cold, and lifeless. There was no perverse pleasure to be found in surrendering to it; the satisfaction rang hollow, his catharsis denied. There was no spark to it. There was no fire.

He closed his eyes, scrubbing his hand over his mouth, and bit the inside of his cheek until he tasted copper.

So this was it, then. He couldn't firebend; he couldn't walk more than a step or two; he couldn't even feel angry properly. The only thing left to do was nothing; feel nothing, bend nothing, accomplish nothing, live like a nothing. He was trapped at the bottom of the world, in the dark and the cold, and no one— _no one_ —knew where he was.

Zuko wasn't sure how long he sat there on the floor, staring into space, forcing his mind to remain blank. He had to come up with some kind of plan to escape, but didn't know where to even start. The view outside his window gave no clues about his location, nor the time of night; the stars shone fiercely and the sky remained inky blue-black, and no matter how long he stared at the horizon he never saw the telltale blush of light that signaled an imminent sunrise.

 _Come on,_ Zuko begged the sun. _Rise. Show me some light. Show me there's something left to hope for._

He kept waiting.

.

" _Spirits,_ you're a piece of work."

His eyes fluttered open and he groaned, partly from stiffness and partly from the sight of Katara hovering above him like a wasp.

"What are you doing here?"

Katara cocked an eyebrow. "I live here," she retorted. "What are you doing on the floor?"

"I—" the details of his meltdown came back in a flash, closing Zuko's throat to whatever excuse had been on the tip of his tongue. Katara rolled her eyes and turned away, gathering the bedding up from where he'd strewn it, remaking the bed with brisk efficiency.

"Listen, I know you're having a rough time of things, but could you try to avoid destroying my home in the process?"

"Excuse me?" Zuko was wide awake now, and glared at her with every ounce of intensity he could muster. For all that he was an exile and an embarrassment, he was still _royalty,_ and it had been a very long time since anyone had dared to speak to him with such audacity.

Katara was unfazed by his scowl. "This is my house. I brought you here? I'm Katara, remember me?"

"I'm not stupid."

"Could've fooled me, but there's always a chance for a miracle."

 _Agni_ , she was quick with a comeback. Zuko tried to stand, but hissed in pain when his whole body ached—revenge for spending the night sleeping on the floor.

Katara circled around the bed and knelt beside him, holding out her hand. "Now," she said, eyes sparkling with equal parts amusement and exasperation, "are you going to behave yourself, or do you need a little more time on the floor to calm down?"

 _If I was anywhere else on earth, I think I might kill this girl,_ Zuko realized. But he nonetheless gripped her offered forearm, with only a small bit of hesitation to placate his pride; Katara pulled him to his feet swiftly and helped him back under the blankets, and then set the side table back upright.

"I brought more food," she said, fetching another tray from the long table near the door. "Unless you'd rather toss it around too."

Now it was Zuko's turn to roll his eyes. "No," he shot back, accepting the tray from her. The food was simple—a seafood stew and a bread roll still warm from the oven—but it was tasty, and gone far too soon. With a full stomach, there were far fewer echoes in Zuko's head, and his irritation began to feel like an old familiar friend.

"Glad you've got your appetite back," Katara grinned. "Your healing will probably go much quicker if you're not hungry."

"I always wanted to get stranded in a Water Tribe hut while a stranger applied walrus blubber to my scrapes and bruises," Zuko grumbled. "I don't have _time_ for this."

Katara looked incredulous. "Did you have an urgent appointment you're going to miss?"

Zuko pressed his lips together and mentally smacked himself upside the head. _Nice going, idiot._

"No," he managed, sounding ridiculously guilty. "I'm—I was on a mission, and I got lost, and I'm hoping to return to my crew when we rendezvous at the Tiger Seal."

It was a messy lie, but a decently believable one, especially if she didn't think he was Fire Nation, though his delivery left something to be desired. If Katara doubted his story—and, really, how could she not—she didn't say anything; she just kept looking at him with that same incredulous expression, and Zuko scowled and looked away, pulling the blankets up over his chest, hoping she'd take the hint and leave him alone.

"For the record, we don't use blubber for healing."

 _Is she still here?_ He huffed. "What?"

Katara's reached for the pouch she wore on her belt, and when she pulled her cupped hand back Zuko could see it was filled with liquid that glowed a bright otherworldly shade of blue. "Spirit water from the pole," she said by way of explanation, tipping her palmful back into the pouch and recapping it tightly. "It's got magic properties that help with healing, but it isn't quick."

"Then what good is it?" he snapped, and she glared.

"It's still _magical_. Boy, you're itching for a fight, aren't you?"

"What good are _you_ , anyway?" he snarled, finding his footing once again in the anger he knew so well. Part of Zuko, the part of him that sounded like his uncle, was pleading for him to stop and be more sensible, but he couldn't help it. "What could be so wrong with me that you'd need to wave some glowing spittle around? I bet you're making it up. I bet you're just keeping me here because you haven't seen a man in a w—"

Zuko was cut off abruptly as Katara slapped him across the face. He gaped, holding a hand to his cheek, as she fixed him with a glare that would make even the boldest Fire Nation admiral flinch.

"Your heart has been frozen," she snapped. "The blizzard's magic got deep into your system and froze your heart, okay? It's slowly turning to ice. Every time it beats, it gets harder and harder, and soon it will freeze completely."

Zuko felt the blood drain from his face, and his heart thudded painfully in his chest. "You—you're joking," he sputtered. "That's impossible."

"I'm not, and it's not," came the response. "I'm researching a permanent cure, but until I find one, I have to go in with the, ahem, _glowing spittle,_ and melt the ice crystals that are forming as we speak. If I don't, you won't even make it back to the Tiger Seal. Believe me or don't; it's your life on the line. I want to help you but if you keep being such a little pissant I swear I'll throw you right back out in the snow."

Silence hovered, heavy and tense, as they glared at each other.

"What about my bending?" Zuko finally asked, sullen.

"Your chi will probably remain blocked until your heart begins to heal properly," she replied. "I can't really say for sure."

"So I might never—" he swallowed. "I might never bend again?"

"Maybe."

He squeezed his eyes shut. _Agni help me._

Katara huffed. "Is your life worth so little to you that you'd rather die than never bend again? Lots of people get through without bending a single thing their whole lives."

"You don't understand," he croaked. "Bending is—it's _part_ of you. I can't just—"

"—sure you can," Katara cut him off. "You think you're the first person in the world to cope with an unimaginable loss?"

Zuko felt himself crumpling. "So those are my options? Stay here or die?"

Katara folded her arms. "You know what I can offer to you. You can take it or leave it."

Somewhere in the back of his mind, Zuko heard his uncle chiding him in his gentle gruff voice: _be nice to her, Prince Zuko. She's taken you into her home and is caring for you sight unseen._ He huffed, shoulders slumping. He might be foolish and hotheaded at times, but Zuko wasn't stupid, no matter what people said; he knew that going back out into the snow would be tantamount to signing his own death warrant. He had no gear, no backup, no bending. Nothing.

 _Nothing_.

Katara was still there, sitting patiently, watching him. Zuko finally flicked his eyes up to meet her gaze.

"Can you fix me?" he asked. Internally, he winced again: _if I have to get used to sounding this pathetic whenever I talk to her, I'll just walk outside and freeze to spare myself the embarrassment. This is humiliating._

Katara nodded. "Yes," she answered. "I think so."

"You _think_ so?"

There was something in the way she straightened her back, chin raised and head held high, that made her seem much taller for a moment. "Yeah. Do you have a problem with that?"

Zuko's eyes narrowed. "It would be nice to get a more definitive answer," he muttered.

"Well, that's all I have for you. I'll do what I can to get you back up on your feet, so you can return to the coast and find your men."

"And my bending?"

She reached over and covered his hand with hers; he snatched his arm back almost by reflex, and tried not to see how her face fell before she replied.

"I honestly don't know. But I'm going to try."

That would have to be good enough. "Fine," Zuko spat. "Do what you need to do." He might be trapped here, but there was no rule that said he had to like it.

"Okay," Katara said. "Lie back down, and, um—" Her eyes slid to Zuko's torso, where he was holding the blankets up over his chest with one fist, and a jolt of emotion shot through him—embarrassment? Shame? Shyness? _Ugh._

He groaned. "Are you _serious_ —"

"I'm afraid I am, yes."

Zuko did _not_ like to be touched, but his uncle always used to say that the most incredible decisions were often made when there was nothing left to lose. "Fine," he said again, settling back in on the bed, suppressing the shiver that passed through him when Katara placed her hands on his chest, directly above his heart. Her brows knit together as she concentrated, eyes flicking back and forth ever so slightly, as if she was dreaming. The water clung to her hands, forming a liquid glove, and the glow seemed to pulse gently in time with his heartbeat. Zuko craned his neck to see what she was doing, but it didn't seem like anything was happening, and boredom almost instantly began to itch at the back of his brain.

Moments stretched into seconds stretched into minutes before the silence became overwhelming and Zuko exhaled through pursed lips.

"How does the spirit water work?"

Katara smiled out of one side of her mouth. "That's a secret," she replied, a hint of steel in her voice, and Zuko rolled his eyes.

"I can't know what you're doing to me?"

"I'm healing you."

He sighed again, for what felt like the hundredth time that day. "Yes, I know that. _How_?"

"It can find the things about you that are broken, and start to fix them," Katara explained.

Zuko scoffed. "That sounds like a whole bunch of nonsense."

Katara arched her eyebrow, giving him a look that was becoming infuriatingly familiar. "Has anyone ever told you that you're a terrible patient?"

He echoed the gesture back at her with his one remaining eyebrow, and jutted out his chin defiantly. "It's been brought up before."

 _Go ahead,_ he goaded her silently. _Look. I know you want to_. And, sure enough, her eyes flicked ever so slightly down from his sight line, sweeping to the left and then upwards and back over—a movement that Zuko had all but memorized by now. He'd seen it in hundreds of people, from loyal Fire Nation soldiers to cowering Earth Kingdom peasants to the rogue pirates who fought for control over the southeastern seas. Everyone took in his scar the same way; everyone got the same look of pity and revulsion, their mouths twitching with unspoken platitudes and their cheeks going pale. Every single time it happened, a part of Zuko always wanted to shrink back from the scrutiny; his left hand twitched with the urge to cover his eye, to turn away, to change the subject. But his scar was the cursed mark of the banished prince; covering it up was an act even more dishonourable than the way he'd acquired it in the first place, and Zuko couldn't afford to lose any more honour than he already had. So he stared back, maintained his eye contact, held his head high. He knew what he looked like; he couldn't hide it, and there was no point in pretending it hadn't happened.

Katara didn't shrink as obviously as others did, which he chalked up to her experience as a healer, and she returned his stare sooner than expected, her eyes filled not with pity but with something far more unsettling: kindness.

"Fire Nation?" The only two words she needed.

"Yes," Zuko answered reluctantly, because it wasn't a lie.

Katara bit her lower lip, and her hands pressed a little harder onto his chest. "I'm sorry."

Zuko lay his head back and studied the ceiling. "Yeah," he replied under his breath, "I am too."

.

The healing session lasted another few hours; Zuko dozed off and awoke to find himself alone once again, with a tray of food on the side table. Beside the bowl sat a scroll of Water Tribe children's stories, with a note attached: _in case you get bored._

Zuko felt the right corner of his mouth tug upwards into a smile, and he scrunched up his face to erase it. Katara was kind, but it didn't change things; he was still trapped, and she was a complete stranger standing between him and his destiny. Until he could fight back, she was an obstacle, if not an enemy.

He ignored the way his heart twinged in his chest, and reached for the scroll anyway.

It was nearly impossible to keep track of the time with any real accuracy, but Zuko began to get a sense of routine based on Katara's comings and goings. She would bring him breakfast in the darkness of morning, then lunch a few hours later, though the sky had barely changed. The little room felt like it was yanked out of time and space, so that nothing changed at all no matter how much time did pass. While the healing sessions weren't painful, Zuko would always find himself tattered from exhaustion afterwards, as if he'd run a very long distance; nonetheless, he started to find that his muscles were gradually getting stronger, his appetite more consistent, his heartbeat more regular. His inner fire remained cold and dead, a fact which Zuko tried his best to ignore; it was easier to pretend, here at the end of the world, that he was someone different. That his bending belonged to another Prince Zuko, a different one who wasn't such a colossal failure, and that he was just a traveler with a similar name and face.

It wasn't going to change things, but it helped prevent him from descending into complete and utter despair.

On the fourth or fifth day, Katara brought two trays of food instead of just one.

"Do you need to check up on me?" Zuko grunted. "I promise I'm eating all of it."

"Nope!" she shrugged. "I just figured you must be getting lonely, here all by yourself. I can leave if you want."

He inhaled, ready to tell her to go, but he didn't, and so she stayed.

What began as one shared meal soon became two, then three, always spent in silence. Katara would spend the time between breakfast and lunch with her hands on Zuko's chest, healing him; the sessions always ended when she began to yawn, so Zuko suspected that she was getting in a brief nap before dinner, but the hallway outside his room was dark and his brief glimpses of it yielded no answers. As Zuko read through the scrolls she brought him, he realized just how little he knew about the Southern Water Tribe. His grandfather had purged the great library of Caldera many years before Zuko had been born, so the sources he had about the other nations had been carefully censored to reflect the Fire Nation's glory above all else. The scrolls Katara gave Zuko didn't contain any information that would be useful to his mission, but he had to admit that the stories were charming; they depicted the South Pole as a world of incredible magic and wonder, instead of the wasteland of cold and darkness that he saw whenever he looked out the window.

"Why hasn't the sun come up?" he asked one afternoon, while Katara pressed her palms to his heart.

She looked over to the window, and a flash of joy crossed her features. "The sun only rises once a year," she replied.

"What?" Zuko bolted upright, almost knocking his head against hers. Katara stepped back, hands raised.

"Yeah. It's—we're at the bottom of the world. It's dark for half the year, and light for the other half."

 _Of course it fucking is_. "Well," is all he could manage to say out loud.

"It takes some getting used to, I'll admit," Katara said, "but it's not all bad. The moon is very beautiful, and the Southern Lights will take your breath away."

Months and months without the sun on his face, without the warmth spreading across his skin and seeping into his soul. Zuko lay back down before Katara had to ask, and squeezed his eyes shut to prevent any tears from escaping.

.

 _In his nightmares, Caldera was bathed in eerie moonlight, the vibrant red decorations of the palace recast in stark black. Zuko sat in his bed, his chambers pulsing with the monsters hiding at the edge of every shadow. A horrifically familiar singsong voice echoed to him from the door, where he could see a black silhouette leaning against the frame._

" _Dad's gonna kill you!"_

Azula always lies, _he whispered to himself, but no sounds came out of his mouth._

" _Come now, Prince Zuko," came another voice, this time breathed directly in his ear. "That's no way to talk about your sister. What kind of Fire Lord will you be if you can't get along with your only sibling?"_

Father _. Zuko flinched, burying his face in his hands, his mind screaming at him too late that he had to stand up straight, had to obey every command, had to be good, had to be good, had to be—_

 _A roaring crowd. The sound of drums in the distance, thudding with ferocious speed like a quickening heartbeat. His chest was bare, his feet rooted to the ground no matter how badly he wanted to run, and when Zuko lowered his arms he saw the fire bearing down on him. He tried to retaliate, but his bending was gone, the connection severed._

No! _he screamed, falling to his knees, and then the scene changed again; he was in the throne room, kneeling on the floor. The throne was surrounded by bright white flames which failed to illuminate the face of the man who sat there._

" _Tell me, Zuko: what good are you, if you can't firebend?"_

 _Zuko closed his eyes. His father had asked him the same question at the age of seven; back then, he had responded with stubborn determination, promising his father that he could and would become a great firebending master. This time, he told the truth:_

None at all. I'm useless.

" _That's right," came the response. "I'm glad we finally agree."_

 _Zuko risked a glance up to the throne._ Please, father, _he said, just as he had so many months before._ Please tell me what I can do to restore my honour and come home.

" _Bring me the heart of the last waterbender," Ozai said, just as he had, and Zuko hung his head in shame._

I got lost, _he whispered, feeling his cheeks get hot._ I don't know where I am.

 _Ozai stood up and walked through the fire, down the steps and across the floor until he was directly in front of where Zuko knelt._

" _That's no matter," he said, teeth flashing white as he grinned. "I've got her right here." With a snap of his fingers he summoned a figure held in chains, her arms spread wide and legs shackled together. She was old, wrinkled and frail, but her eyes were bright and blue and clear. Zuko looked down to find a knife in his hand, the blade shining as it reflected the flames around him._

 _Zuko felt his heart drop to his toes._ Wait, but I—

" _I know you can't do it," Ozai sneered. "Why do you think I sent you to the very bottom of the world? You're never coming back. You'll never regain your honour. You don't have the guts to do what it takes to be Fire Lord. You're_ nothing _. You'll never—"_

 _And then Zuko was on his feet, charging, yelling, plunging the knife into the woman's chest; and as Ozai's laughter filled his ears Zuko looked into the face of the last waterbender and for just a second she looked just like Katara—_

.

He snapped awake with a jolt, heart racing, limbs frozen in place.

"Hey," came Katara's voice, slow and calm. "Are you alright? Was it a nightmare?"

Zuko managed to nod, stiffly jerking his head up and down as his eyes raced over Katara's body, searching for a knife hilt, for blood, for the shadow of his father standing just behind her.

"You're, uh—you're crying. I think."

Adrenaline was still coursing through him, making it impossible to feel anything else, so Zuko sat up and accepted the handkerchief she handed him without hesitation. "Sorry," he rasped, dabbing at his right eye.

Katara smiled. "It's okay, really," she said. "We've all had bad dreams."

 _I bet mine are scarier than yours,_ Zuko thought, breathing deeply and listening to his heartbeat slow and stabilize. "How long were you standing there?"

"It's only been a few minutes. You fell asleep, so I figured I'd just keep going and finish the session. I hope that was okay."

His father's laughter was still ringing in his ears, making Katara sound very far away, so Zuko just nodded. "S'fine," he mumbled. "I'll try not to fall asleep again."

Katara sat on the edge of the bed, close to his right hip. "Can I ask you a question?" she said softly.

"I—yeah."

Her eyes moved back and forth as she searched his face. "Were you dreaming of…" she trailed off, but her gaze had landed squarely on his scar, and Zuko sighed silently.

"Yeah," he replied. "Among other things."

"When was—"

"—I don't want to talk about it," he said, bracing himself for the usual flash of pity, but Katara shrugged.

"Okay," she agreed. "We don't have to talk about it. But...listen, this spirit water is powerful. I could—I don't want to presume, but...I could try to heal that. If you want." She gestured to the pouch at her waist.

Zuko's heart skipped a beat.

"You can heal this?" he whispered.

"I think it's possible," she said. "Probably worth a try. Do you want to?"

Zuko blinked as his father's words echoed. _You're never coming back. You'll never regain your honour. You don't have the guts to do what it takes to be Fire Lord. You're nothing._

 _Bring me the heart of the last waterbender._

"Maybe," he finally said. "When I'm finished with my mission."

"And when will that be?" Katara asked.

He thought of the waterbender in his dream; of the fear in her eyes, the lines on her face, the way she looked horrified and disappointed as the knife sank into her chest. He looked away.

"When I've done the worst thing you can possibly imagine."


	4. Three: faced with the ice

_The candle was pristine, white wax with a neatly trimmed wick, positively begging to be lit._

 _"Go on, Prince Zuko. Try it again."_

 _He was small again, sitting in Master Kunyo's chambers, his fingers still stubby with baby fat._ I'm trying, _he whined._ It won't work.

 _"It's easy, Your Highness. Just snap your fingers—" he demonstrated "—and draw from your inner fire, through your root. Keep yourself grounded, and don't forget to breathe."_

 _It all seemed like far too much to do at once, but Zuko squinted in deep concentration as he inhaled, exhaled, grounded himself, and—_ snap.

 _A tiny flame appeared in his palm, flickering and sickly, winking out before he had the chance to touch his hand to the candle. Zuko felt a sob bubbling up through his throat._

I can't do it, _he whispered, his cheeks burning with shame._

 _Master Kunyo scoffed. "Of course you can, Your Highness. You've done it before."_

No, _Zuko said, his voice deeper now, his hands longer, his left eyelid pulled taut from scar tissue._ You don't understand. My fire, it's—it's gone.

 _"Your fire is always with you, Prince Zuko," Kunyo smiled. "It will never be snuffed out. The inner flame of a firebender is as eternal and powerful as the sun in the sky."_

 _Zuko felt ice spreading with every beat of his heart._ I've lost it, _he cried, shoulders shaking._ It's been snuffed out and I don't know who I am anymore.

 _"I know who you are," came a different voice, and Zuko found himself back in the throne room, staring at the shadowy silhouette of his father. "You're exactly who I knew you would be at birth. I should have thrown you over the city walls when I still had the chance."_

 _Zuko turned to see the waterbender suspended in chains, only this time it was undeniably Katara who hung there, arms pulled out to her sides and head dropped to her chest._

 _"What will you do, when you face her?" his father sneered. "How will you fight if you can't bend?"_

I know how to fight, _he responded stubbornly, wincing as his voice cracked._ I don't need fire to defeat an old woman.

 _"Then do it," Ozai commanded, and the three words reverberated through Zuko's entire body like particularly painful heartbeats._

 _Zuko felt the weight of the knife in his hand. He was already running towards her, arm raised, ready to strike, when Katara looked up, right at him, and the blue of her eyes was like a blazing beam of light. Zuko ground to a halt, his heart thudding painfully in his chest, each beat knocking him down like a punch: he fell to his knees as Ozai's mocking laughter filled his ears. Zuko watched the shadow of his father bend over Katara, a fireball already in hand, and no matter how he tried he couldn't manage to scream—_

 _._

His eyes snapped open and he just barely failed to muffle his gasp as the last of the dream left him; he breathed in shudders, inhaling deeply and exhaling slow, trying to stop his heart from racing.

"Nightmare again?" came Katara's voice, and Zuko turned to see her sitting at the large table in the corner, eyes still focused on the scroll in her hands. His body hadn't fully adjusted to the complete lack of sunlight, which meant that he often fell asleep in the middle of the day, so it wasn't uncommon to see Katara in his room when he woke up.

He ran a hand through his hair, which had grown enough that the root of his Phoenix Tail was no longer visible. "Yeah," he replied hoarsely. "No chance you can cure those?"

Katara pursed her lips as she thought. "I mean, I can give you some wine, if you want. It might not cure the nightmares but you probably wouldn't care as much."

Zuko took a solid breath before he made an effort to hide his smirk. In the past week or so, he and Katara had fallen into a fairly comfortable routine of healing and rehabilitation; he was getting stronger, but it didn't take long before his heart would give out and he'd find himself weak-kneed again. Katara was a genuinely excellent healer, for all that Zuko sometimes suspected that their sessions were an excuse for her to touch his chest ( _how long had it been since she'd seen another human being? Did she have a husband? There was no ring on her finger, but Agni only knew what kind of betrothal signs they used all the way down here, if they even did_ ). She never brought up his scar, which was a blessing, and Zuko refrained from asking her any questions about herself, for fear of what she'd ask of him in return.

"Want some dinner?" Katara said, snapping Zuko from his reverie. He nodded, pulling on the greenish-brown robe she'd given him, and she smiled. "Think you can make it to the table this time?"

"Sure."

She came over, wrapping an arm around his back and helping him to his feet, steadying him as his knees wobbled.

"I feel like a baby fox antelope," Zuko complained, to which Katara laughed.

"I wouldn't know," she replied. "I've never seen one. But if they're as jittery as you, it's a wonder they're still around!"

"They're pests," he admitted through gritted teeth as he sat in a chair. "Invasive species, where I'm from."

Katara grinned. "Well, you're enough of a pest that I'd believe it."

"You've got a terrible bedside manner."

"And you're a terrible patient. We're perfect for each other."

Instead of dignifying that with a response, Zuko studied the wall beside him, watching as the thin coating of mist curled up and down like a gentle ghost. He reached out to touch it, furrowing his brow as he realized—

"Ice." He murmured the word mostly to himself, wondering how he'd never taken notice before.

"Yes," Katara said, setting two plates down on the table. "The water vapour provides extra insulation, so we don't have to bundle up indoors."

 _That's smart,_ Zuko thought. _Too smart for a Water Tribe girl to do alone. It had to be—_

"The waterbender made this, didn't she?" he muttered under his breath. Katara sat down across from him and picked up her spoon.

"A very long time ago," she replied, her voice matter-of-fact. "Before I was born."

Zuko couldn't help himself; he pounced, asking the question that had been haunting him ever since he'd woken up after the storm:

"So the waterbender is real, then?"

Katara tilted her head, watching him watch her, before finally answering. "Yes. She's real."

 _She's real._ Zuko felt his heart pound against his ribs.

Katara said it so off-handedly, so easily, as if it wasn't information that could change Zuko's life forever. As if he hadn't been sitting in limbo for weeks now, suspended in time and space, and all he'd had to do this whole time was ask her. His hand dug into the flesh of his thigh under the table as he fought to keep his tone casual.

"D-do you know her?"

"I don't think anyone really knows her, but I've met her, yes," Katara said. Zuko blinked, and she smirked. "What, surprised I'd talk about her at all to you?"

"I, well. Yeah."

She shrugged. "Why else would you have been out here, this far south? You're not the first person I've come across who was looking for her. Not the first to almost die of hypothermia, either." Her mouth flattened. "I know you're dying to ask me about her, so just do it. Though just to get it out of the way, her heart is _not_ made of gold."

This was unprecedented. Zuko could feel a million questions crowding against his mouth, each fighting to be asked first, all threatening to erupt out of him at once like a volcano.

"Did the waterbender create the blizzard?" the words escaped before he could stop them, and Katara pursed her lips in thought.

"Hmm. Not directly, but her presence does increase the potency of the magic around these parts."

"Will you take me to her?" Zuko cringed internally, digging his nails into the skin of his thigh. _Why can't I interrogate people properly, damn it?_

A small chuckle. "Why? What use is she to you?"

"I—" Zuko faltered.

 _Bring me the heart of the last waterbender._

He cleared his throat. "It's about my mission. I need her help."

Katara swallowed her stew. "And what makes you think she's interested in your mission?"

 _She's playing with you,_ he realized. Just a few weeks ago, this kind of coyness would have sent Zuko into a rage; now, sitting across the table from this infuriatingly mysterious creature who was challenging him at every turn, he just looked down and traced a droplet of water across the surface of the table.

 _She has information,_ he thought. _It doesn't hurt to be nice and get what you need. It doesn't make you any softer than you already are._

"I don't," he finally said. "But I'm...it's my last chance to set things right, and go home. It's my destiny to meet her." And kill her.

"Destiny, huh?" Katara rolled a bit of bread between forefinger and thumb. "You really believe in all of that?"

"Of course. Don't you?"

Her lips pursed as she thought. "No, I don't think I do. I think destiny is actually incredibly cruel."

Zuko bristled. "How can you say that?" he retorted, unable to mask the emotion in his voice. "It's the one thing that gives life meaning!"

"That's not true at all."

His eyes narrowed. "How do you know?"

"Because the waterbender had a destiny once," Katara said, cradling her chin in her hand.

He blinked. "She...what? _Once_? You don't have a destiny _once_ , like you see fireworks _once_ or witness a rabid armadillo lion _once_. It's something you have forever, until you fulfill it."

Katara shook her head. "A hundred years ago, when the Fire Nation first began invading our land, the Southern Water Tribe elders came together in an historic meeting; every leader, every healer, every man or woman who was considered wise, they all gathered to discuss how they might deal with the imminent threat of destruction. The Fire Nation had once been an important ally to the Water Tribe, but relations had grown distant in the past few hundred years, and let's just say that occupation and death was a less than ideal reunion option.

"The Southern Water Tribe did not have very many treasures to share, and their resources would only appeal so much to Fire Nation folk. Our military forces were a fraction of the size, and most of our waterbenders were killed in the first few battles. At the time, the elders weren't sure if the Fire Nation would try to establish diplomatic relations and colonies like they were doing with the Earth Kingdom, or if they were going to try and wipe us from the face of the earth. Faced with the potential decimation of our people, the elders voted to give the Fire Nation their most precious asset: the last waterbender left alive. She would be betrothed to a member of the Fire Lord's inner circle, in an effort to secure a truce between the two nations."

"That doesn't sound so bad," Zuko said.

Katara recoiled. "Are you kidding?" she asked. "She was the last person to hold the most powerful secrets of her people, and she was to be given away like chattel, to live out the rest of her life in a land that hated her, married to a man she did not love, treated like a pawn in a political gambit that might not even pay off. The waterbender knew the truth: the Fire Nation would never stop, not until they'd brought the entire world under their thumb and eradicated the traditions of anyone who wasn't like them. So instead of obeying, the waterbender gathered the precious treasures of the Southern Water Tribe, and she fled to the very tip of the Pole, where it was too cold for most other humans to survive. She built a fortress of snow and ice, hidden by multiple storms, and she's been there ever since."

 _Multiple storms_. Zuko swallowed the lump in his throat. How close had he gotten to the waterbender before he succumbed to the blizzard? How close had he been to fulfilling his quest, only to fail again, like he always did?

He shook his head of the thought and forced his mind back to the conversation at hand. "So she left her people to fight on their own, and lose," he said. "That's the most selfish thing I've ever heard in my life. Her destiny was to save her people, and she ran away instead."

Katara shook her head. "I disagree," she replied. "The Southern Water Tribe has survived through the war by virtue of being inconspicuous and innocuous enough to avoid seeming like a significant threat. She removed the things that would make the Fire Nation interested in us, and has kept them safe ever since. Sometimes you need to carve a new path through the snow, no matter how hard it may be."

Zuko thought of his struggle through the snowbanks and exhaled through puffed cheeks. "If you say so," he muttered. "I still think she should have stayed and fought."

"She could have died, and then we'd have been even worse off," Katara said. "The Fire Nation is savage and cruel, especially to benders. This way, the Southern Water Tribe could claim that all their benders were gone, sparing countless innocent villages from raids. We were able to survive, in this new world the Fire Nation wrought. Sometimes that's enough."

He felt a familiar pang of shame. "The Fire Nation thinks that the war is about bringing glory to savages, to shining a light in dark places."

"Oh? And how do you know that?"

He blanched, mentally scrambling for an excuse. "Oh, I, um. I've spoken to them, during my travels." _It's not technically a lie_."I've been all over the world, and I've seen what the war has done to the citizens of the occupied nations. It's...not been pretty."

In this, at least, Zuko could be truthful.

Katara sighed. "You're lucky," she replied. "I've spent my life stuck here at the Pole. I've always dreamed of seeing the other nations with my own eyes. Even the Fire Nation, for all that it's full of murderers. I hear the capital city is lovely."

Zuko returned his gaze to the table and shivered as he imagined the warmth of the sun on his skin. "It's the most beautiful place on Earth," he murmured despite himself.

"Have you been there?"

 _Me and my big mouth._ "I—um. Yes. A few times." _Please stop asking questions,_ he begged silently, feeling his pulse increase.

Katara's eyes narrowed. "I'm sorry, I—for some reason I thought you were from the Earth Kingdom."

Zuko forced out a weak chuckle, his heart beating so fast he was sure he'd keel over and die right there at the table. "How could you tell?"

"Well, you had the shaved head but no tattoos, so you probably aren't an Air Nomad," she counted off on her fingers. "I'd know in a heartbeat if you were Water Tribe, but you're definitely aren't from around here. And judging by your...well. The Fire Nation wouldn't burn one of their own like that, so that leaves Earth Kingdom."

 _You'd be surprised what the Fire Nation can do_ , Zuko thought bitterly, but outwardly he nodded. "You're right. I'm—from Ba Sing Se. My mission has been...very far-reaching. We've had a chance to go to places that most others wouldn't." He paused, and then: "like the South Pole, for instance."

 _Tell me more about the waterbender,_ is what he meant.

"You'll have to tell me about your travels sometime," is what Katara said, with a finality to her tone that added _and if you're smart you'll accept the change of subjec_ t.

Zuko forced his lips into a grimace he hoped seemed casual. "Maybe." He pushed around his stew a few times, his appetite gone, and waited for the resulting awkward silence to become amicable again as his thoughts roiled.

 _You're lying to her. She would hate you if she knew who and what you really are. You're too cowardly to take pride in your heritage. She's going to find out sooner or later, and then she'll hate you even more._

It was funny how those thoughts always sprang to mind in his father's voice.

"Wait," Katara blurted suddenly, and Zuko jumped, dropping his spoon with a clatter.

"Y-yes?"

She regarded him with a skeptical squint, pausing for a moment that felt to Zuko like a million years before she finally spoke.

"...Did you say you saw a rabid armadillo lion?"

Zuko almost collapsed with relief. "Yeah," he replied. "On the outskirts of the Earth Kingdom, on a...a hunting trip with my uncle when I was fourteen."

Katara pressed her fingers to her mouth. "Oh my god," she whispered behind her hands. "That must have been _terrifying_. "

Against his better judgement, Zuko nodded. "It wasn't fun, I'll tell you that," he said. "We didn't even try to hunt it; we just turned around and ran."

"Did it chase you?"

The curiosity and passion in her voice was infectious, and Zuko felt his heartbeat quicken as he leaned forward, a real smile tugging at the corner of his mouth. "If it had, I wouldn't be sitting here today. But as it was, I saw my fifty-seven-year-old uncle climb a tree faster than a fox squirrel to get away from that thing. And by that I mean he _literally_ outraced a fox squirrel."

Katara burst out laughing, her voice like pealing bells, severing the tension that had been pulling at Zuko's mind; and as she peppered him with further questions, he felt an odd blush of warmth across his chest for the first time in weeks, and all he thought was: _oh_.

.

After that dinner, something shifted. Zuko didn't spend the healing sessions awkwardly staring at the ceiling anymore; he found himself instead visualizing his heart, imagining Katara melting the ice crystals and restoring him back to full health, day by day. Their meals were never spent in silence again; while she was infuriatingly tight-lipped about the waterbender no matter how casually Zuko asked, Katara was utterly fascinated by the world outside of the South Pole, and her questions about Zuko's travels were blessedly limited to general inquiries that allowed him to give as much or as little detail as he wished.

And, remarkably, he _did_ give details, telling her stories of the things he'd seen during his banishment, always careful to omit the specifics of why he'd gone traveling in the first place. Always smoothing over the rough details to erode the painful truth of the uniform he'd worn, the entourage he'd taken, and the rejections he experienced over and over again as word of the banished prince spread. Those six years had passed for Zuko in a cloud of shame and self-loathing; but here, in Katara's hut, where he didn't ever have to touch the thorny question of _why_ , the memories seemed less painful to recount. Perhaps it was denial, or perhaps just weak will, but Zuko found that if he pretended he was this other person—just an Earth Kingdom boy with a scar, with no royal title or disappointed father or damaged honour—then it was also possible to ignore the hollow and cold place in his chest where his inner fire no longer burned. It was possible to pretend that he wasn't in the middle of a mission that would dictate the course of the rest of his life, and to suppress the haunting echo of the ticking clock in his mind—at least while he was awake. His dreams never got any easier; the nightmares were a vivid rush of all the things he managed to forget during the day, always tormenting Zuko with the secrets he kept and jolting him awake just in time to feel his rapidly beating heart undo all the progress Katara had made the day before.

Perhaps she sensed this, because she began to spend more and more time in his room, and was quick to lay a water-covered hand on Zuko's chest to help calm his racing pulse. Aside from their shared meals and healing sessions, Katara had taken to studying her scrolls or hemming clothing during the lazy hours in between, and Zuko had picked up his own minor habit of watching her work, looking for the charming little furrow of her brow and the way her tongue would stick out of the corner of her mouth when she was particularly engrossed in her task.

It may have continued this way forever, too, but for the fact that just as Zuko was starting to loosen his grip on his destiny, it literally landed back in his lap.

"Is this yours?" Katara asked, dumping the pack at the foot of the bed. Zuko's eyes widened, and he crept forward to get a closer look, fingers trembling.

Everything was still there. His clothing, his hair ties, even his compass. They had been cleaned and dried, as if they'd never been lost at all.

Zuko felt his mouth go dry. "Where did you find this?"

Katara shrugged. "The storms take and the storms give," she said. "It turned up half-buried in a bank near the fishing hole."

Zuko dug into the pack, fingers carefully walking past item after item, until they brushed against the most precious things of all: his dual broadswords. He swallowed, pulling his hand out of the pack without removing them.

 _What will you do when you face her?_ the spectre of his father had asked. _How will you fight if you can't bend?_

He had known the answer then and he knew the answer now; the solution sat heavy in his lap. He looked back up at Katara, hoping his eyes didn't betray the emotions flitting through his mind.

"Thank you," he rasped, and Katara smiled.

"Might be nice for you to have proper clothes that fit again, instead of what I can whip up."

Zuko nodded numbly. "Yeah," he replied, gazing back down at his belongings. "Might be nice."

He felt the bed dip as Katara sat down nearby, and watched her fidget with her fingers out of the corner of his eye.

"Zuko—I want to ask you something."

The swords. He froze, sweat beading on his brow. He was a fool to think she wouldn't have seen them; obviously someone had spent time cleaning and drying his belongings, and unless Katara was hiding a full waitstaff somewhere, Zuko knew it had to have been her. He took a deep breath.

"I can explain—"

Katara shook her head. "No, I have a request." She reached out and took Zuko's chin in one hand, raising his head so that their eyes met, and he tried in vain to stop himself from trembling.

"What is it?"

Her eyes were huge. "You're going to recover at some point, and you're going to leave this place," she murmured. "And when you do...I want you to take me with you."

 _Bring me the heart of the last waterbender._ Zuko gulped, words rushing to his mouth before his brain could stop them.

"Take me to the waterbender, and I will."

A flash of hurt crossed Katara's face. "Oh," she breathed. "I...I don't know if I can do that."

Zuko fiddled with the edge of his pack, shame rising to heat his cheeks. "I need to go to her," he whispered. " _Please_."

But she was already pulling away, already rising off the bed, already shutting him out. "Zuko, there are things—it's complicated. I'm sorry. I can't."

She was gone before he could put together the words to stop her.

Zuko was left alone, staring blankly at the pack in his lap, letting the gravity of its presence seep into his soul. Last time he had seen his belongings, he had been so determined, so focused, so ready . So prepared to kill an innocent human being, in the hope of finally redeeming himself in his father's eyes. The items seemed like relics of another life, but it was his life, and there was no denying it.

 _Bring me the heart of the last waterbender._ His quest; his curse; his destiny, however cruel it may be. It was still his, and sooner or later Zuko was going to have to claim it.

With a long sigh, he fell back on the bed, arms spread wide against the quilts. Katara was right; at some point he would be healed, and then he would have to leave this place. And there was a part of Zuko that wanted very badly to take her with him, to show her some of the things he'd described, to see her face light up with joy at the sight of the giant unagi that lived near Kyoshi Island and the majestic heights of the Western Air Temple.

 _Bring me the heart of the last waterbender._ Zuko covered his face with his hands and groaned.

It was going to come down to a choice, and a fairly painful one if he was honest. But wasn't that the way with all grand destinies? The road always forked, and the paths always beckoned with equal temptation, but in the end you could only ever walk down one.

Behind his hands, Zuko closed his eyes and listened to his heart beat. He knew his path: he was going to recover, walk out that door, and find the last waterbender of the Southern Water Tribe. He was going to cut out her heart and take it back to his father, and then he would be restored to his rightful place and everything would be okay again. He would finally be home, and things would be as they had once been, whether his scar remained or not. That was what he'd been working towards, for nearly a decade now; Caldera was his shining city on the hill, beaming with promise and hope. If only he could get there.

It was probably going to be messy. Zuko knew that. Katara was smart; she would likely guess his intentions, and he wasn't sure he'd be able to convincingly lie. He was going to have to deal with that, somehow, and the taste of metal seeped into his mouth at the thought. Once upon a time, this situation would have been easily resolved; he would have gotten the information he needed, knocked her out, left her for dead, and moved on without a backwards glance. But it didn't feel right, thinking of it now. It didn't feel honourable.

What was it that Uncle Iroh had always said? _There is no honour to be found in winning with manipulation and betrayal, Prince Zuko._

He sighed. He was still recovering; there was still time to figure out what he was going to do, and maybe even convince Katara that he was trustworthy enough to learn the whereabouts of the waterbender. _No matter what happens, I'll make sure no harm comes to Katara,_ Zuko promised himself. _And if I manage to get out of this alive, if I'm successful in my quest, then I'll send her enough gold that she'll be able to travel the world on her own._

Zuko had been dealt his fair share of shoddy Pai Sho tiles in the past, but this one in particular felt like a kick in the gut.

When he eventually drifted off to sleep, he did not dream.

.

 _"Zuko. Wake up. She's here."_

He opened his eyes, blinking into the dark, as the voice of his father faded from his mind. It was late; the lamps had burned themselves out, and only the light of the full moon outside kept Zuko from being completely in the dark. He sat up, heart beating steadily, and furrowed his brow as the feeling in his mind refused to fade. The moon seemed to be calling to him, the dancing Southern Lights throwing the world into eerie shades of blue and purple.

Zuko crept out of bed, walking softly and slowly, drawn to the door like a moth to flame. He rested his hand on the knob for a moment, his heart in his throat, before turning it slowly.

In the weeks he'd spent here, Zuko had never left his room. Katara had dodged his questions about it, promising to show him around when he was strong enough.

As Zuko pulled the door open, he smiled mirthlessly. He seemed strong enough tonight.

Even so, he walked slowly, bracing himself against the wall with one hand. The hallway was dark, but as Zuko's eyes adjusted, he realized that he'd never seen a Water Tribe hut like this before. The hall was too long, too wide, too pristine. He passed other closed doors—one, then two, then so many more that he lost count, as it became clear that this place was much, much larger than he had first thought. The water vapour from the walls swirled around his feet.

Someone was humming in the distance, a mournful and gentle tune that reverberated through the empty corridors— _Katara_. He winced as his heart thudded painfully, but pushed forth, step by step, following the sound until he rounded a corner to find himself in a large courtyard. It was full of stone benches and had a huge frozen pond in its center, pristine in the moonlight, dusted with lightly falling snow. And there was Katara in the middle, wearing a beautiful dress, her eyes closed as she hummed to herself, twirling around in a private dance.

 _What the hell?_ Zuko blinked and rubbed his eyes, because on second glance the snow _wasn't_ falling around her; it wasn't snow at all, but rather individual droplets of water hanging in midair, twinkling like tiny diamonds. And the pond wasn't frozen; Katara was dancing _on_ the surface of the water, her bare feet kicking up tiny splashes with each step, and the push and pull of her arms—

Zuko felt the blood drain from his face; his knees went out from under him, leaving him sagging against the wall, unable to do anything but look at her, as horror and dread crept up to stick painfully in his throat and his heart pounded against his ribs.

 _Bring me the heart of the last waterbender._

He watched her lift her arm like a concert composer, and every tiny droplet rose at her command, floating up over their heads until the moon above seemed studded with gems.

 _Wake up. She's here._

It was Katara.


	5. Four: i need your heart

_Bring me the heart of the last waterbender._

This was impossible.

 _Bring me the heart of the last waterbender._

Why? _Why_? Why her? How could this be?

 _Bring me the heart of the last waterbender._

Zuko clamped a hand over his wide-open mouth, trembling all over. His heart was racing, his pulse roaring in his ears.

 _Close your eyes,_ he told himself. _Try to slow down your h—_

 _Bring me the heart of the last waterbender._

He couldn't. Couldn't move, couldn't breathe, couldn't speak, couldn't calm down, couldn't stop looking at her. Katara's expression was beatific, her face tilted upwards to the moon, basking in its cool light in the same way that Zuko would turn his face towards the sun. The water droplets twinkled, refracting the Southern Lights, covering the whole courtyard in tiny circles of blue and purple that shifted and swayed with the aurora above. Katara smiled joyfully, her eyes full of wonder, clearly relishing the beauty of it all; she was ethereal, unhurried, bending just for the art of it. As Zuko watched, her grin became mischievous, lower lip caught briefly between her teeth; then, with a flick of her fingers, every droplet exploded into mist. He flinched violently as the spray hit his face, a gasp escaping from between his fingers before he could stop it.

 _No!_

But it was too late; Katara looked over, their eyes locked, and her expression vanished. She took two leaping steps across the surface of the pond before landing on the ground, and Zuko prayed to every god he'd ever heard of to just _get moving, please, please just_ run—

His feet finally got the message and he pushed away from the wall, running as fast as he could, deeper into the depths of the fortress, as Katara called after him:

"Wait! Zuko, please, wait!"

 _No_ , he thought as he rounded a corner and ducked through the gap between two absolutely gigantic doors, pushing them shut behind him with a groan. He turned to find himself in a ballroom, bigger than anything the Fire Nation Palace could possibly offer, its ice block parquet floor shimmering in the moonlight. All around him, the water vapour from the walls curled and wafted, reaching out for him with tiny tendrils.

Zuko felt his pulse pounding in his throat, his head spinning and his knees threatening to fold where he stood. He staggered to the wall, leaning on it for support as he pushed himself through each next step, overwhelmed with thoughts of _keep going, don't stop, get out._

"Zuko!" she was still calling for him, chasing him, going to catch him.

His heart was so rapid, every beat echoing through his body, as if his veins were all pulsing along in time with it. He reached the other side of the ballroom and slipped through the first door he saw, into another hallway, which led him to a grand foyer with twin staircases curving up to— _a second floor? Agni, is she serious? Doesn't matter._ He scrambled up the stairs, almost on all fours, unable to trust himself to walk without collapsing.

No time. No time. No time. Keep pushing, keep going, one more step, one more—

"Zuko, _please_!" Katara cried, closer this time, and at the sound of her voice his focus slipped for a fraction of a second, but it was enough. His knees gave out and he went sprawling across the ice floor, sliding until he hit the wall with a faint _thud_.

"Zuko?"

He looked up to see her standing at the other end of the hall. As she approached, he pushed himself up on shaking hands, panting from the exertion, as the most curious feeling began to spread through his core. Despite the fact that Zuko was lying on a floor made of solid ice, his limbs weren't chilly; but his chest felt deeply, profoundly cold, and his heartbeat was sluggish, trudging, slowing— _stopping?_

Right at that moment, Zuko felt his lungs collapse. He looked down, pawing at his tunic, fingers grazing against skin that was frozen and blue like a corpse.

 _Every time your heart beats,_ she'd said. _The ice crystals will form._

He gasped for air, trying and failing to fill his lungs, and his vision began to swim as Katara reached him, her hands reflexively flying to her side only to come up empty.

 _The spirit water,_ Zuko realized, as his mouth opened and closed like a fish. _She doesn't have it._

And then: _I'm going to die here._

She knelt down in front of him, reaching forward; Zuko couldn't shrink from her hand, so he could only watch as Katara pulled open his tunic, hovered her palm a few inches above his heart, blew a strand of hair out of her eyes, and then closed her hand into a fist and _tugged_.

Zuko arched off the floor, screaming soundlessly as something in his chest seized and was pulled impossibly tight, as if the very cells themselves had gone rigid. Then the cold feeling began to dissipate; he could suddenly breathe again, his teeth chattering violently, every movement pure agony. Katara's face filled his field of view, and she cupped his face gently in her hands.

"Breathe," she whispered. "Slow and easy. And if you feel like passing out, don't fight it."

 _She brings warmth,_ Zuko thought, and then the pain overwhelmed him and pulled him down into the dark.

.

When Zuko next opened his eyes, he was in a bedroom—a different one from the place he'd spent the past few weeks. This one was much larger, the bed huge and lush, surrounded by four posters made of ice with draping fabric hung in between. His whole body felt like it had been fed through one of the Fire Nation's huge wall-destroying drills.

Katara was nearby, curled up on a chaise lounge that wouldn't have looked out of place in Zuko's own chambers at the palace in Caldera, but for the fact that it, too, also seemed to be made of ice. She looked asleep, her face illuminated by the moonlight; but upon hearing Zuko stir, she opened her eyes and looked at him as if she'd been waiting for hours. They regarded each other for a while in silence, and then she sighed.

"You're an idiot."

Zuko would have screamed if he had the strength; as it was, he could only gape at her. "Are you fucking _serious?_ "

Katara scowled. "You can't go running off like that, all panicked and erratic! Your heart was starting to freeze solid!"

"No thanks to you!"

If glares could cut flesh, Zuko would be ribbons. "I saved you, dummy. _Again_. You're welcome, by the way."

"What did you do to me? With the, um—" he curled his hand into a fist and made a sharp yanking motion.

"I melted the ice crystals," she replied. "All of them, all at once."

Zuko groaned as he remembered the awful taut feeling in his heart, and the _shift_ as it vanished all at once; a shudder of pain went through his whole body. "What is _wrong_ with you?"

"Nothing!" she snapped, jumping to her feet, her voice echoing through the room. "There is _nothing_ wrong with me. And stop yelling; you shouldn't be exerting yourself, remember?"

"Well _you_ shouldn't be—" Zuko faltered, then regrouped. "Also, you're the _waterbender_?!"

Katara exhaled a shaky breath before nodding. "Yes. I'm the last waterbender of the Southern Water Tribe."

 _Bring me the heart of the last waterbender._

There she was. She'd been under his nose the whole time.

 _Agni._ Zuko tipped his head back against the headboard. He should be interrogating her, dragging her back to where he kept his swords, getting the deed over and done with so he could go home. Instead he was sitting here, barely alive, in her house, his life now indebted to her twice over.

 _She's close enough to take down and I've got the constitution of a wet noodle. Just another day for Prince Zuko, soon-to-be-former-Royal Failure._

Zuko shook his head, clearing the thought before he could dwell any more on it, and fixed his glare back on Katara.

"You lied to me," he rasped.

"I know. I'm sorry," Katara replied, coming over to sit on the edge of the bed, either not noticing or not caring when he flinched away from her. "You have to understand, I'm a secret. No one can know who or what I am. All the adventurers who make it this far, I just heal their frostbite and send them back on their way. None of them ever know."

"Well. The honour is all mine, then, I guess." Zuko couldn't keep the bitter edge out of his voice. "So, while we're being honest: why have you been faking healing me with that spirit water this whole time? Why didn't you just do this—" he gestured to his chest "—when I first got here?"

"The spirit water is real," Katara said. "I couldn't risk using my bending on you, not so obviously; the spirit water makes the process less...abrupt. And I would have continued doing that, but...well. No secrets during an emergency, I suppose." She looked down, fiddling with the edge of a quilt. "It's not a permanent fix, by the way. Your heart is still frozen; the ice crystals will come back. I'm working on it. I don't think there was any damage to the soft tissue of your heart, but I'll have to check later—"

He was already shaking his head. "No," he whispered. "No way. I'm not letting you touch me ever again."

Katara stopped fiddling, her expression unreadable. "So be it," she murmured.

Zuko scowled. "Really?"

"I'm a healer. I respect your autonomy."

"Some healer you are," he grumbled, mostly to himself. "You damn near killed me."

"Well that wouldn't have happened if _someone_ had stayed in his room like he was supposed to," she retorted.

"Well maybe if you hadn't lied to me from the moment I saw you, I wouldn't have been suspicious! Ow!" Zuko yelled, as his heart twinged painfully. Katara huffed.

"Would you please calm down? I promise I'm not going to hurt you. I'll answer your questions."

He couldn't help but cock an eyebrow at her. "Oh, so now you're going to be forthcoming?"

She spread her hands, palms upturned. "I don't really have a choice, do I? You're not supposed to know who I am, and you do, so now I have no idea what to do with you."

 _Bring me the heart of the last waterbender._ Zuko had an idea of what to do with her, and at that moment he couldn't tell if the task seemed especially horrible in light of this new revelation, or whether it had always haunted him and he was in too much pain to pretend otherwise.

 _I'll answer your questions._ That's good; he had about a million of them. He always seemed to, with Katara. She created more mysteries than she solved, and it was fucking infuriating. Where to even start?

Zuko squinted. "How come you don't look a hundred years old?"

Katara chortled. "Because I'm not?"

"...what?" he blinked. "But, I thought—isn't the last waterbender—how could all the stories exist if you're so young? What about that story of how you ran away? Of being engaged to someone from the Fire Nation?"

There was a flash of something sorrowful in Katara's smile. "That all happened," she replied. "But it didn't happen to me."

 _Why do girls always talk in circles like this?_ Zuko would have thrown up his hands in frustration, if he could lift his arms. Katara swung her feet up onto the bed, leaning against one of the far posts and crossing her legs at the ankle, and Zuko snorted derisively.

"Making yourself comfortable, aren't you?"

She gave the facial equivalent of a shrug. "What can I say? I like this room."

"Well you sure do have a lot of them."

"Mm. Yes, I suppose I do."

His eyes narrowed. "Did you build this place?"

Katara shook her head. "No. My grandmother did. Well, my adopted grandmother."

Zuko blinked. "Your...what?"

Now Katara broke eye contact, her tongue coming out to wet her lips. "The story I told you was true," she said. "A hundred years ago, the last waterbender of the Southern Water Tribe was promised to a Fire Nation noble. Her name was Unne, and her betrothed was a man named Roku."

"Roku?!" the word escaped from Zuko's mouth before he could stop it, and Katara narrowed her eyes suspiciously.

"Yeah. You know him or something?"

 _Fuck, Zuko, will you ever learn to shut your big mouth?_ He cleared his throat. "I, uh. I'm familiar with the name."

That raised eyebrow of hers was going to be the death of him. "Learn that from your travels, did you?"

"I had a lot of interest in Fire Nation history," he replied, because it wasn't technically a lie. "For a little while, anyway."

Katara seemed to buy it. "Well. Unne and Roku, they didn't hate each other; not the way people say, anyhow. It seems that at one point—before Fire Lord Sozin's war transformed him into a mass murderer—Roku did possess some kindness and empathy. I think he did care for Unne, and she cared for him, but she knew she could never go through with the arrangement. She held a secret that not even the Tribe elders knew; something passed from waterbender to waterbender, and never shared with anyone else. And so, just before the Fire Nation delegation was set to depart, Unne ran. She came here, and she built this place, to shield herself and the ancient secrets of the waterbenders from the rest of the world. But Unne brought with her a brand new secret, too: she was pregnant."

"Oh," Zuko said. That was all he could say.

"She gave birth to a daughter, Hama. And for seventy years, the two of them lived here, cut off from the rest of the world. Unne passed down to Hama all of her knowledge."

"And Hama is your mother?"

There it was again, that flash of sorrow, or perhaps something even harder. "No," Katara replied, a hair too sharply. "Hama was not my mother. When Unne died, Hama was well past her childbearing years. She was powerful too, maybe even more powerful than Unne. She was able to seek and find power using her mind's eye, able to pull water out of things you wouldn't imagine. So she kept tabs on all the Southern Tribes, searching for a baby girl who was a waterbender, and when the opportunity came, she...took it."

Zuko swallowed the lump in his throat. "Did you know your fami—"

"—I was an infant. I've only ever known this," Katara gestured around them. "Hama raised me, taught me, showed me everything she knew. She died, a few years ago. And I've been here alone ever since."

Zuko's heart jabbed him again, and he winced.

"Careful," Katara murmured, coming forward again to sit on the edge of the bed by his leg. "Don't overdo things."

"I'm not," he mumbled.

Her sigh seemed to hold the weight of the entire fortress around them. "So. Now you know what I am. The last waterbender."

"I suppose I do. And I'm—" Zuko stopped as Katara's face fell. "What?"

"Leaving."

He glared. "Pardon?"

Katara looked up to meet his eyes, and he was struck with how vulnerable she looked. "You were going to say that you're leaving, right?"

Was he? "I—"

"—please don't go," she blurted, squeezing her eyes shut as if the words hurt to speak. "Please, Zuko. Please don't leave."

It wasn't the sorrow in her voice that gave him pause; it was the fear. The quiver of her lip, the way her whispers were edged with tears, the wavering tone that gave away just how hard it was speak those words out loud. He swallowed.

 _Bring me the h—_

 _—oh, shut it, I know. Let me think for a second._ He furrowed his brow, trying to reconcile the Katara in his mind—hemming a sleeve, laughing over breakfast, hands steady on his chest—with the inconceivably powerful bender sitting before him, whose death was the key to the rest of his life.

 _No matter what happens, I'll make sure no harm comes to Katara,_ he'd said. Every part of his rational mind screamed that harming her was exactly what he'd have to do, but try as he might Zuko couldn't summon even a tiny flicker of anger, never mind the homicidal state he'd have to occupy in order to fulfill his destiny.

He was exhausted. It seemed to happen a lot, with Katara around. He had to grant that it was a pretty effective way to extend her own life, even if she didn't realize it. The revelation of her identity didn't change the mission; it just made things a whole lot more complicated, and sometime soon—when he didn't feel like he'd been run over by a tank—Zuko was going to have to ask some horrendously difficult questions. Why had his heart frozen, and not any of the others? What good was his honour if it meant killing a smart and sweet girl like Katara? What good was his honour if it came from killing _anyone_ in cold blood?

 _Bring me the heart of the last waterbender._

He could never forget what he saw, but why did part of him wish she hadn't said it out loud?

Out of all these questions, the mystery why she wanted to keep him around was perhaps the least horrifying to ponder, and the curiosity was just too strong to resist. Zuko sighed.

"Give me one reason to stay."

"You'll die if you leave."

He shook his head. "Not good enough."

Katara fixed him with a very familiar look of exasperation, and a small part of Zuko wanted to smile even as her glowering intensified.

"That's not good enough?" she asked, and against his will Zuko's mouth turned upwards. He bit his lower lip until the urge passed.

"No," he finally replied, short and sullen.

"...I'll kill you if you try to leave." From the quavering in her voice, it was clear that Katara didn't believe that any more than Zuko did, and now he did smirk.

"I'd like to see you try."

Her hands clenched and released. "I can heal you."

"So could another healer. I know some very good ones."

Katara wrapped her arms around herself, and somehow in that moment seemed younger than her years. "Fine. The truth is…I need your help."

He laughed, just once. "What could you _possibly_ need from me?"

The light of the full moon streamed in through the window, and Katara turned her head towards it, just as she had in the courtyard. "I draw my power from the moon," she explained. "I don't know if you knew that. I don't know how much you know about waterbending. And—well, you've noticed that it's dark pretty much all the time right now, but it's not going to remain that way. In a few months, the season is going to change, and the sun will come up, and it will be daytime for half the year; I'll still have my abilities, but I won't be as powerful." She looked back down, shoulders sagging. "Last year, when the summer ended, I had a vision that a monstrous man would come to this place, and when the sun rose again, he would cut out my heart."

 _Oh,_ Zuko thought. _...oh._

Katara sat up straight again, and wiped an invisible tear from her face. "Anyway. The vision showed me that I can't defeat this man, not as I am right now. I saw your swords, and I thought...you know how to use weapons, how to take down an enemy the old-fashioned way. I can bend, but I—I don't think it's going to be enough. I know it's a lot to ask, for you to fight a battle that isn't yours, but...if I can heal your heart, and maybe even your bending, would you stay and help me defeat him?"

Zuko was still too stunned to say a word.

"You don't have to answer right away. I'm sure you have more questions," Katara said. "For now, you should rest. You should recover fairly quickly, if you behave." She stood up from the bed without looking at him, and walked towards the door.

"Wait—" he blurted, and she turned back.

"Yeah?"

A million questions. Always a million questions, with her. Never anything simple. Zuko swallowed.

"Where am I right now?"

At this, Katara's mouth pulled upward into a half-smile.

"You're in my bedroom," she answered cooly, "for the first and last time."

And then she left, and Zuko was alone.

.

 _In his nightmares, Zuko stood at the very bottom of the world and watched the sky brighten, ink black transforming slowly to dark grey, then to blue. He closed his eyes as the first rays of sunlight pierced the horizon line, a blast of warmth hitting his face, like the embrace of an old and beloved friend._

It's time, _he thought to himself, as a knife appeared in his hand. He turned to see Katara standing on the courtyard pond, dancing alone. Her face was serene, her eyes closed, a tiny smile lifting her lips. She would never see it coming._

 _Zuko took one step towards her, then another; she remained oblivious, occupied instead by the thousands of diamonds that swirled around her, each gem reflecting the beams of the sun at Zuko's back. She was the waterbender, and she was beautiful._

 _"She was, wasn't she?" came a voice, and Zuko looked over to see a man dressed in traditional Fire Nation garb, his beard neatly trimmed and his hands tucked into his sleeves._

What are you talking about? _Zuko snarled quietly, careful not to disturb Katara's dance, even as the man looked over at her._

 _"Unne. She was beautiful," the man replied, and with a start Zuko realized where he'd seen the man before:_

Roku?

 _"What will you do, Zuko?" Roku asked, only now it was Zuko's own voice coming out of his mouth. "What are you going to do?"_

 _Zuko readjusted his grip on the knife._ What I came here to do, _he answered. He took another step, and his foot plunged into snow that came up to his thigh, pitching him forward. He dropped the knife as he fought to regain balance, and the noise punctured the quiet stillness of the morning and finally got Katara's attention._

 _"What's going on?" she asked, taking two steps across the surface of the pond and leaping down to stand over him, tall and graceful._

Nothing, _Zuko said, but as the word echoed around him he felt the sun's warmth dip, and a chill shot through him as a shadowy figure approached Katara from behind._

 _"Zuko? Are you okay?" she asked softly, walking over to kneel by him. "Is it your heart?"_

 _There was a blast of heat, and the unmistakable crackle-whoosh as flames surrounded them. The shadow loomed, tall and broad, and chuckled in a leering tone that sent shivers up and down Zuko's spine._

 _"Yes, Prince, what about your heart?" Ozai sneered. "More importantly, what about hers?"_

Stay away from her! _Zuko yelled, but it wasn't his voice; in the blink of an eye, he was now behind Katara, sneaking up on her, the fire in his veins flowing hotter and stronger than he thought imaginable. Roku lay where Zuko had been just a moment ago, looking up desperately at him._

 _"Please," he begged. "Please don't—"_

 _But Zuko was already reaching out, already plunging the knife into Katara's chest, already watching the blood stain her dress the rough purple-black of a fresh bruise. He looked up into Katara's eyes, wide with shock and betrayal, and in her final moments she reached a trembling hand out and gently cupped his cheek—_

.

Zuko opened his eyes slowly this time, lips already pursed, ready to slow his heartbeat, but—

 _Wait._

He sat up. He was still in Katara's bedroom; she had lit the lamps at some point, and now the space was bathed in rich warm light. And...and—

Zuko brought a hand to his chest. His heart was beating steadily, calmly, kindly; the details of his nightmare had faded already, leaving only a ghost of the feeling behind, and it, too, was retreating with every breath.

"Was it a good dream, this time?" Katara asked. He turned to see her on the chaise lounge again, dressed back in her casual attire; two trays of food were set on the table nearby.

"No," Zuko shook his head. "But...this time I feel different."

Katara grinned. "Good. That's really good."

He blinked. "I...yeah. It is. That's…" he looked back up at her. "Why?"

"Bending," she answered. "Now that you know I'm a waterbender, I don't have to limit myself. You've made decent progress with the healing sessions, but the ice crystals still form in between, and every time they do, they set you back just a little. So I figured, instead of waiting for them to build up and having to melt them in one session, I can just...prevent them from forming at all. See how your heart does if given a real chance to recover. Your chi, too, maybe."

Zuko swung his legs over the side of the bed and stood up, solid and unwavering. He felt stronger than he had in weeks. He felt _warm_ , like the sun was at his back _._

"Huh," was all he could say. "That's...I guess that is useful. How do you do it?"

Katara tapped the side of her head. "I just have to concentrate a little. A lot of this place is held together by the will of the last waterbender, so it's not much more work to also concentrate on you. And this way, I don't have to touch you ever again, if you don't want me to."

Zuko couldn't stop himself from smirking. "Does that mean you're thinking of me constantly?"

She mirrored his expression. "Maybe. Will you think of me in return?"

"If it means I can feel like this all the time? Sure."

It was amazing, to be able to just walk over to the table with no wobble in his knees or lightheadedness tipping him over. Zuko sat down in front of one of the bowls of stew, and Katara joined him a moment later, and for a fraction of a second it really seemed like nothing had changed at all.

 _Bring me the heart of the last waterbender._

Except, of course, everything had changed forever.

"So," Katara said, "have you given any thought to my request?"

 _What will you do, Zuko?_ The voice bubbled up from his subconscious, familiar and hauntingly strange all at once. A remnant from his dream, though the speaker's face was fuzzy in his mind.

 _What are you going to do?_

Zuko didn't know who was asking, but he shuddered as he felt a phantom hand cup his cheek, like a memory of something that had never happened at all. He exhaled, smooth and slow.

 _She was beautiful, wasn't she?_

"I can't defeat this man for you," he said softly, hiding his wince as Katara's face fell. "But...I can train you to fight back."

 _What will you do, Zuko?_ _Something stupid, that's what._

It was almost worth it for the way Katara's face lit up. "Thank you," she gushed. "So much, Zuko. You have no idea how grateful I am for your help."

 _You say that now,_ he thought, ripping up his roll, unable to eat despite his stomach grumbling. _But you're going to regret it later. And so will I._

He risked a glance back up at her. "So, um, I have a question," he began, feeling his cheeks get hot as he realized how tentative he sounded.

"Hit me."

"You said—earlier, when you brought me my pack. You asked me to take you along when I left this place." Zuko rubbed the back of his neck, which was an old nervous habit, and his fingers jolted ever so slightly to find that the skin back there was just as hot as his face felt.

Katara froze, spoon halfway to her lips. "Oh. Um. Yes."

"Why? If you're the waterbender, shouldn't you want to stay here?"

From the way her shoulders shrank, Zuko could tell that he had touched on something very painful. Katara's eyes lost their spark, and it was almost like watching a mask click into place. "Don't worry about it," she said, too casually. "Forget I said anything."

"But—"

"—Zuko, please, just...forget it, okay? I shouldn't have asked you. I don't want to talk about it."

He could respect that. He had to, all things considered.

"Okay," he replied. "We don't have to talk about it." If he had his way, they would avoid talking about certain topics for years, maybe forever.

 _Bring me the heart of the last waterbender._ Every second he stayed here, Zuko was betraying Katara. He knew it, and it made him feel worse than dirt. Six years of aimless banishment were going to seem like a cakewalk by comparison.

Katara wiped her mouth with her handkerchief. "Good. And you should eat, your stew will get cold."

"Right," he said, snapping out of his reverie and turning his attention back to his food. The bowl was indeed cool to the touch; Zuko raised a spoonful of stew to his mouth and blew on it by force of habit before swallowing—"ow!"

"What? Don't tell me you broke a tooth, I soaked those sea prunes for _days_."

"No," Zuko replied around the stew, "it's just hot, that's all." He swallowed, grimacing as the food burned its way down his esophagus, and Katara furrowed her brow.

"Huh, I thought I tested the temperature before I brought them up," she said. "That's strange. Must have mistimed things."

Zuko wiped his mouth on the sleeve of his robe. "It's okay," he replied. "I'm—"

 _Wait._

He barely managed to avoid dropping his spoon, setting it back on the table with a trembling hand as he realized what he'd just done.

"Everything okay?" Katara sounded very far away, and Zuko forced himself to nod.

"Yeah. I'm just not as hungry as I thought, I guess."

"Hmm. Well, I'll leave it for you, just in case," she said, standing up with her own tray. "I'm going to go put this away; I'll be back, and maybe we can take you to your room again?"

He nodded again, head jerking up and down mechanically as Katara left the room. As soon as the door closed behind her, Zuko jumped out of his chair, sending it clattering to the floor, and he screwed his eyes shut, hands curled into fists so tight that his arms ached.

 _Come on,_ he begged, searching deep. _I felt you. I swear, I—_

He stopped, one hand coming to rest on his sternum.

It was tiny, barely more than an ember, struggling to survive beneath the imposing black and cold. It was too weak to be used, probably too weak to be fed, liable to snuff out instead of catching and growing. It was hardly anything at all, and as Zuko watched, it faded almost completely away. But he swore it was there.

Tears sprang to his eyes, and he let them fall.

Inside, deep in his core, something was burning again.


End file.
